EFFECT OF COBALT IN THIN WALL DUCTILE IRON AND SOLID SOLUTION STRENGTHENED FERRITIC DUCTILE IRON

Ductile Iron is a material that is constantly evolving. Consequently, the ferrous industry is not only focusing on lightweighting but also on improving the impact strength and fracture toughness of typical ferritic-pearlitic ductile iron grades and solid solution strengthened ferritic ductile irons. Recently, the demand for thin-wall ductile iron and solid solution strengthened ferritic ductile iron grades has increased. The challenges behind the fabrication of these two ductile iron materials are the presence of carbides and the embrittlement of ferrite. In response, research has been focused on looking at alternative methods that can mitigate carbide formation in thin sections and counteract the detrimental effects of high silicon contents in the impact toughness of these materials. One way to reduce carbides is by increasing the silicon, but high silicon contents embrittle the ferrite and result in low static and dynamic mechanical properties. Cobalt in ductile iron is known to increase the nodule count resulting in a higher ferrite content in the as-cast condition, and it also hardens the ferrite via solid solution strengthening. Therefore, the ability of cobalt to inhibit carbide formation and its effect on the toughness of two different types of ductile irons was studied. Firstly, it was found that the addition of 4 wt.% Co reduces carbides in thin sections with a silicon level around 2.41 wt.% Si. Secondly, partial substitution of silicon with 2 wt.% and 3 wt% Co provided higher strength in a 600-10 SSFDI grade. Nonetheless, the impact strength and fracture toughness were not improved with cobalt additions. It was established that cobalt increases the ductile to brittle transition temperature

Influence of Cobalt in the Tensile Properties of ½ Inch Ductile Iron Y-blocks

The ferrous industry keeps evolving, and the demand for castings with complex geometries is increasing. Due to this, some foundries are facing several challenges when it comes to producing highly complex parts with a specific microstructure. Normally, heat treatment is performed when a ferritic matrix is desired. However, distortion and cracking can become a problem too. Because of this, it is important to explore alternative methods that can potentially help with these problems. In ductile iron, cobalt additions are known to increase the nodule count, which favors higher ferrite fractions. Hence, the addition of cobalt was studied to investigate its effects on the microstructure and tensile properties of ductile iron. Five heats were produced and cast into ½ inch ASTM A536 Y-blocks: 0 wt%, 1 wt%, 2 wt%, 3 wt%, and 4 wt% Co. Metallography was performed to evaluate the percent nodularity, nodule count (N/mm2), and ferrite/pearlite percentages. Tensile testing was executed using sub-size round samples. Brinell hardness and micro-Vickers were conducted on each Y-block to assess the macro and microscopic behavior of the cobalt bearing ductile iron. The addition of 4 wt% Co was found to decrease the nodule size and increase the percent nodularity and nodule count resulting in higher ferrite contents. Cobalt did not have a statistically significant effect in tensile strength and percent elongation. However, cobalt was found to increase the yield strength due to the solid solution strengthening effect in ferrite

Platelet Membrane: An Outstanding Factor in Cancer Metastasis

In addition to being biological barriers where the internalization or release of biomolecules is decided, cell membranes are contact structures between the interior and exterior of the cell. Here, the processes of cell signaling mediated by receptors, ions, hormones, cytokines, enzymes, growth factors, extracellular matrix (ECM), and vesicles begin. They triggering several responses from the cell membrane that include rearranging its components according to the immediate needs of the cell, for example, in the membrane of platelets, the formation of filopodia and lamellipodia as a tissue repair response. In cancer, the cancer cells must adapt to the new tumor microenvironment (TME) and acquire capacities in the cell membrane to transform their shape, such as in the case of epithelial−mesenchymal transition (EMT) in the metastatic process. The cancer cells must also attract allies in this challenging process, such as platelets, fibroblasts associated with cancer (CAF), stromal cells, adipocytes, and the extracellular matrix itself, which limits tumor growth. The platelets are enucleated cells with fairly interesting growth factors, proangiogenic factors, cytokines, mRNA, and proteins, which support the development of a tumor microenvironment and support the metastatic process. This review will discuss the different actions that platelet membranes and cancer cell membranes carry out during their relationship in the tumor microenvironment and metastasis

The complete mitochondrial and plastid genomes of Corallina chilensis (Corallinaceae, Rhodophyta) from Tomales Bay, California, USA

Genomic analysis of the marine alga Corallina chilensis from Tomales Bay, California, USA, resulted in the assembly of its complete mitogenome (GenBank accession number MK598844) and plastid genome (GenBank MK598845). The mitogenome is 25,895 bp in length and contains 50 genes. The plastid genome is 178,350 bp and contains 233 genes. The organellar genomes share a high-level of gene synteny to other Corallinales. Comparison of rbcL and cox1 gene sequences of C. chilensis from Tomales Bay reveals it is identical to three specimens from British Columbia, Canada and very similar to a specimen of C. chilensis from southern California. These genetic data confirm that C. chilensis is distributed in Pacific North America